> -----Original Message----- > From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx] > Sent: Sunday, March 1, 2015 7:34 PM > To: Jake Oshins > Cc: rafael.j.wysocki@xxxxxxxxx; KY Srinivasan; linux-kernel@xxxxxxxxxxxxxxx; > devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx; > vkuznets@xxxxxxxxxx > Subject: Re: [PATCH 1/3] drivers:pnp Add support for descendants claiming > memory address space > > On Tue, Feb 17, 2015 at 11:41:49AM -0800, Jake Oshins wrote: > > This patch adds some wrapper functions in the pnp layer. The intent > > is to allow memory address space claims by devices which are > > descendants (a child or grandchild of) a device which is already part > > of the pnp layer. This allows a device to make a resource claim that > > doesn't conflict with its "aunts" and "uncles." > > > > This is useful in a Hyper-V VM because some paravirtual "devices" need > > memory-mapped I/O space, and their aunts and uncles can be PCI devices. > > Furthermore, the hypervisor expresses the possible memory address > > combinations for the devices in the VM through the ACPI namespace. > > The paravirtual devices need to suballocate from the ACPI nodes, and > > they need to avoid conflicting with choices that the Linux PCI code > > makes about the PCI devices in the VM. > > > > It might seem like this should be done in the platform layer rather > > than the pnp layer, but the platform layer assumes that the > > configuration of the devices in the machine are static, or at least > > expressed by firmware in a static fashion. The nature of a Hyper-V VM > > is that new devices can be added while the machine is running, and the > > potential configurations for them are expressed as part of the > > paravirtual communications channel. This much more naturally aligns > > with the pnp layer. > > > > Signed-off-by: Jake Oshins <jakeo@xxxxxxxxxxxxx> > > --- > > drivers/pnp/Makefile | 2 +- > > drivers/pnp/base.h | 2 + > > drivers/pnp/core.c | 1 + > > drivers/pnp/descendant.c | 117 > +++++++++++++++++++++++++++++++++++++++++++++++ > > include/linux/pnp.h | 23 ++++++++++ > > 5 files changed, 144 insertions(+), 1 deletion(-) create mode 100644 > > drivers/pnp/descendant.c > > At first glance, this looks ok. Does it change the sysfs layout of hyperv > devices? > > also, I'd like KY to sign-off on it, verifying that he at least tested the series and > it works for him. Greg, Dan had some comments that Jake will address and resend. Also, we are waiting for Rafael to review this patch. Regards, K. Y > > thanks, > > greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
